The present invention relates generally to a surface mount type semiconductor device having a lead-less structure, and more particularly to a semiconductor device and a method of manufacturing the same in which common parts can be used among semiconductor devices having different package sizes.
Recently, packages of components such as semiconductor integrated circuits, transistors, diodes and the like are downsized and made thin. In such components, existence of connecting leads gives large influence on the package size. Therefore, there is proposed a surface mount type semiconductor device having a lead-less structure in which connecting leads are not used. Especially, in a semiconductor integrated circuit device, it is required that a disposition pitch of connecting leads of a lead frame is minute, in order to realize a device having many lead pins. Also, width or thickness of each lead must be reduced and there is a possibility that the leads bend easily, causing short circuit between the leads. Alternatively, it is required that the package size is enlarged to realize a large disposition pitch of the leads.
Japanese patent laid-open publication No. 9-162348 discloses a semiconductor device having such lead-less structure. FIG. 40 is a cross sectional view of the semiconductor device disclosed in Japanese patent laid-open publication No. 9-162348. As shown in FIG. 40, a semiconductor element (element chip) 303 is fixed onto an element fixing resin board 301, and the upper side and peripheral area of the semiconductor element 303 are molded by package resin 305. Also, there are provided a plurality of projected portions 307 on the bottom surface of the package resin 305. The surface of each of the projected portions 307 is coated by a metal film 309. The metal films 309 are electrically coupled with the semiconductor element 303 via bonding wires 311, within the package resin 305. Thereby, the metal films 309 function as mounting electrodes for mounting the semiconductor device onto a printed circuit board and the like. Thus, in the semiconductor device shown in FIG. 40, mounting electrodes are formed directly on the bottom surface of the package, and it is not necessary to use a lead-frame. Therefore, it is possible to avoid the above-mentioned disadvantages caused by the lead-frame. Also, the package is effectively downsized and made thin.
Japanese patent laid-open publication No. 9-252014 discloses another semiconductor device of this type. FIG. 41 is a cross sectional view of a semiconductor device disclosed in Japanese patent laid-open publication No. 9-252014. The semiconductor device of FIG. 41 is fabricated as follows. First, a metal foil is shaped into predetermined patterns to form a die pad portion 401 and a plurality of electrode portions 403. On the die pad portion 401, a semiconductor element 405 is mounted by using mounting material 407. The electrode portions 403 are then electrically coupled with the semiconductor element 405 by using bonding wires 409. Thereafter, the semiconductor element 405 and the bonding wires 409 are molded by package resin 411. In the semiconductor device shown in FIG. 41, the electrode portions 403 are exposed at the bottom surface of the package resin 411. Thereby, it is possible to realize a surface mount type semiconductor device having a lead-less structure. Thus, it is possible to downsize and thin down the package. In Japanese patent laid-open publication No. 9-252014, a method is also disclosed in which, before patterning a metal foil, a semiconductor element is mounted on the metal foil and wire bonding is performed, and thereafter the metal foil is patterned into desired patterns. Also, Japanese patent laid-open publication No. 10-22440 discloses a technology similar to that described above.
Further, there is known a technology disclosed in Japanese patent laid-open publication No. 8-115989 and Japanese patent laid-open publication No. 8-115991. FIG. 42 is a cross sectional view of a semiconductor device disclosed in Japanese patent laid-open publication No. 8-115989 and Japanese patent laid-open publication No. 8-115991. The semiconductor device shown in FIG. 42 has a frame-like terminal portion 501, and a plurality of column-like terminal portions 503 which are disposed within the frame-like terminal portion 501 and which are insulated from each other and from the frame-like terminal portion 501 via resin portion 505. A semiconductor element 509 is disposed on a patterned layer 507 formed on the frame-like terminal portion 501 and the column-like terminal portions 503. The semiconductor element 509 is electrically coupled with the patterned layer 507 via bonding wires 511. Thereby, the semiconductor element 509 is electrically coupled with the column-like terminal portions 503 via conducting pattern portions of the patterned layer 507. Further, the semiconductor element 509, the bonding wires 511 and the like are molded by resin 513. In this semiconductor device, the column-like terminal portions 503 are disposed in an area just under the semiconductor element 509 as electrodes for mounting. Therefore, it is possible to realize a semiconductor device having a grid array structure.
In each of the conventional semiconductor devices mentioned above, a relatively large number of fabrication steps are required and fabrication process becomes complicated, thereby manufacturing costs are increased. That is, in the semiconductor device shown in FIG. 40, it is necessary to provide the projected portions 307 at the bottom surface of the package resin 305, and to form the metal film 309 on the surface of the projected portions 307. The method of manufacturing such semiconductor device disclosed in Japanese patent laid-open publication No. 9-162348 is as follows. First, a metal base member is formed in which recessed portions are provided at portions corresponding to the projected portions 307. The metal film 309 is then selectively formed in each of the recessed portions. Then, mounting of the semiconductor element 303 and electrical connection between the semiconductor element 303 and the metal film 309 via bonding wires 311 are performed. Thereafter, molding by the package resin 305 is performed. The metal base member is finally removed to fabricate the semiconductor device. In this method, number of processes for selectively forming the metal film 309 is relatively large, and it is necessary to use the metal base member which becomes unnecessary after the completion of manufacturing. Therefore, manufacturing cost of the semiconductor device becomes large.
In the semiconductor device shown in FIG. 41, an etching process is required to pattern a metal foil into desired patterns when the die pad portions 401 and the electrode portions 403 are formed. Therefore, manufacturing process becomes complicated. Also, it is necessary to use a base member for supporting the metal foil when the metal foil is patterned. Since this base member becomes unnecessary after manufacturing the semiconductor device, it causes an increase in the manufacturing cost of the semiconductor device, as in the semiconductor device shown in FIG. 40. When the metal foil is patterned after packaging the semiconductor element, the base member becomes unnecessary. However, since the etching process is performed by wet etching, it is necessary to perform water-resistant protection of the package when the etching is performed. Therefore, manufacturing process becomes complicated and, in this respect, manufacturing costs of the semiconductor device become large.
Further, in the semiconductor device shown in FIG. 42, the pattern layer 507 is required between the frame-like terminal portion and the column-like terminal portions 501 and 503 and the semiconductor element 509 mounted thereon for selectively and electrically coupling the bonding wires 511 with the column-like terminal portions 503. Therefore, a large number of components are required and manufacturing costs of the semiconductor device become large. Also, number of manufacturing processes increases and manufacturing process becomes complicated.
Also, the above-mentioned conventional semiconductor devices have common problems as follows. In order to fabricate the above-mentioned semiconductor devices, components such as the metal film portions 309, the electrode portions 403 each made of a metal foil, the column-like terminal portions 503, the pattern layer 507 and the like are required as mounting terminals. It is necessary that these components are previously designed and manufactured into predetermined electrode arrangement patterns and sizes in compliance with kinds and sizes of the semiconductor elements 303, 405 and 509. Therefore, when a semiconductor element having different kind or size is to be mounted, it is necessary to again design and fabricate the above-mentioned components having different patterns and sizes. Also, when the components are to be previously fabricated and prepared, it is necessary to prepare a plurality kinds of components applicable to a plurality kinds or sizes of semiconductor elements. Therefore, manufacturing and management of the components used for fabricating the semiconductor devices become complicated.
Therefore, it is an object of the present invention to provide a surface mount type semiconductor device having a lead-less structure and a method of manufacturing the same in which the above-mentioned disadvantages of the prior art technology can be obviated.
It is another object of the present invention to provide a surface mount type semiconductor device having a lead-less structure and a method of manufacturing the same in which a simplified structure of the semiconductor device and a simplified manufacturing process thereof can be realized.
It is still another object of the present invention to provide a surface mount type semiconductor device having a lead-less structure and a method of manufacturing the same in which common parts can be utilized for making the semiconductor devices having different kinds and sizes.
According to an aspect of the present invention, there is provided a semiconductor device comprising: a semiconductor element; a plurality of divided segments formed by dividing a conductive plate, at least one of the divided segments being electrically coupled with an electrode of the semiconductor element; and a resin material portion supporting the plurality of divided segments and the semiconductor element together.
In this case, it is preferable that the at least one of the segments electrically coupled with the electrodes of the semiconductor element constitute lead pad portions as mounting electrodes, and at least one of other segments among the plurality of segments constitute die pad portions on which the semiconductor element is mounted.
It is also preferable that, among the plurality of segments, at least one of the segments located under the semiconductor element constitute die pad portions, and at least one of the segments which are disposed in the peripheral portion of the segments constituting the die pad portions and which are electrically coupled with the electrodes of the semiconductor element via bonding wires constitute lead pad portions.
It is further preferable that the resin material portion seals the semiconductor element and the bonding wires, and fills the space between the segments as the lead pad portions among the plurality of segments.
It is advantageous that the semiconductor element is mounted on the at least one of the segments as die pad portions via mounting material or tape-like adhesive.
It is also advantageous that a part of the segments located under the semiconductor element constitute die pad portions, and other part of the segments located under the semiconductor element are electrically coupled with electrodes of the semiconductor element via bumps and constitute lead pad portions.
It is further advantageous that the resin material portion seals the semiconductor element, and fills the space between the semiconductor element and the segments located under the semiconductor element and the space between the segments located under the semiconductor element.
It is preferable that the plurality of segments are formed by dividing a conductive plate into a lattice-like arrangement.
It is also preferable that each of the segments has a crank-like cross section in the direction of thickness of the conductive plate.
It is further preferable that the plurality of segments are disposed around the semiconductor element but are not disposed under the semiconductor element, at least one of the segments are electrically coupled with electrodes of the semiconductor element via bonding wires and constitute lead pad portions as mounting electrodes, and the resin material portion seals the semiconductor element and the bonding wires and fills the space between respective segments of the plurality of segments.
It is advantageous that the semiconductor element is a semiconductor integrated circuit chip, and electrodes of the semiconductor integrated circuit chip are respectively coupled with the segments as lead pad portions among the plurality of segments.
It is also advantageous that the semiconductor element is a diode chip, the diode chip is mounted on one of the plurality of segments, and an electrode of the diode chip is electrically coupled with other one of the segments adjacent the divided segment on which the diode chip is mounted.
It is further advantageous that the semiconductor element is a transistor chip, the transistor chip is mounted on one of the plurality of segments, and electrodes of the transistor chip are electrically coupled with two of the segments adjacent the divided segment on which the transistor chip is mounted.
It is preferable that a ball-like electrode is formed on the backside surface of the at least one of the segments constituting said lead pad portions.
It is also preferable that the bumps are solder bumps or studbumps.
It is further preferable that a resist film is formed on the backside surface of the at least one of the segments constituting said die pad portions.
It is advantageous that an outer dimension of a group of the segments which constitute the die pad portions and the lead pad portions is larger than an outer dimension of the semiconductor element.
It is also advantageous that an outer dimension of a group of the segments which constitute the die pad portions and the lead pad portions is substantially equal to an outer dimension of the semiconductor element.
According to another aspect of the present invention, there is provided a method of manufacturing a semiconductor device comprising: preparing a conductive plate; forming concave trenches in the conductive plate to form a plurality of segments; preparing a semiconductor element; mounting a semiconductor element on the conductive plate having the concave trenches formed therein; disposing resin material on the conductive plate wherein a part of the resin material enters at least a part of the concave trenches; and removing the backside portion of the conductive plate so as to expose bottom portions of the concave trenches.
In this case, it is preferable that, in the removing the backside of the conductive plate, the backside of the conductive plate is polished or etched so as to expose bottom portions of the concave trenches.
It is also preferable that, in the mounting a semiconductor element on the conductive plate, the semiconductor element is mounted on at least one of the segments; wherein the method further comprises electrically coupling electrodes of the semiconductor element with segments disposed around the at least one of the segments on which the semiconductor element is mounted; and wherein, in the disposing the resin material on the conductive plate, the semiconductor element and the bonding wires are sealed by the resin material, and the resin material fills the concave trenches between segments disposed around the at least one of the segments on which the semiconductor element is mounted.
It is further preferable that, in the preparing a semiconductor element, a semiconductor element having bumps formed thereon is prepared; wherein, in the mounting the semiconductor element on the conductive plate, electrodes of the semiconductor element are electrically coupled with at least one of segments disposed under the semiconductor element via the bumps; and wherein, in the disposing the resin material on the conductive plate, the semiconductor element is sealed by the resin material, and the resin material fills a space between the semiconductor element and the conductive plate.
It is advantageous that, in the forming concave trenches in the conductive plate to form a plurality of segments, the concave trenches are formed in lattice-like arrangement.
It is also advantageous that, in the forming concave trenches in the conductive plate to form a plurality of segments, the concave trenches are formed by using a technology selected from a group consisting of half-cut dicing, half-etching and press working.
It is further advantageous that, in the mounting a semiconductor element on the conductive plate, the semiconductor element is mounted on the conductive plate via mounting material or tape-like adhesive.
It is preferable that the method further comprises caving a portion of the conductive plate to form a concave portion, before the mounting a semiconductor element on the conductive plate; wherein, in the mounting a semiconductor element on the conductive plate, the semiconductor element is mounted in the concave portion via mounting material; wherein the method further comprises electrically coupling electrodes of the semiconductor element with segments disposed around the concave portion via bonding wires; wherein, in the disposing the resin material on the conductive plate, the semiconductor element and the bonding wires are sealed by the resin material, and the resin material fills the concave trenches between segments disposed around the concave portion; and wherein, in the removing the backside portion of the conductive plate, the mounting material is exposed.
It is also preferable that the semiconductor element is a semiconductor integrated circuit chip.
It is further preferable that the semiconductor element is a diode chip; wherein, in the mounting the semiconductor element on the conductive plate, the diode chip is mounted on one of the plurality of segments; wherein the method further comprises electrically coupling an electrode of the diode chip with one of the segments adjacent the divided segment on which the diode chip is mounted via a bonding wire; and wherein, in the disposing the resin material on the conductive plate, the diode chip and the bonding wire are sealed by the resin material, and the resin material fills the concave trench between the divided segment electrically coupled with the electrode of the diode chip and the divided segment on which the diode chip is mounted.
It is advantageous that the semiconductor element is a transistor chip; wherein, in the mounting the semiconductor element on the conductive plate, the transistor chip is mounted on one of the plurality of segments; wherein the method further comprises electrically coupling electrodes of the transistor chip with two of the segments adjacent the divided segment on which the transistor chip is mounted via bonding wires; and wherein, in the disposing the resin material on the conductive plate, the transistor chip and the bonding wires are sealed by the resin material, and the resin material fills the concave trenches between the segments electrically coupled with the electrodes of the transistor chip and the divided segment on which the transistor chip is mounted.
It is also advantageous that, in the disposing the resin material on the conductive plate, the resin material is disposed by using a technology selected from a group consisting of molding by a metal die, coating, and potting.
It is further advantageous that, in the preparing a semiconductor element, a plurality of semiconductor elements are prepared; wherein, in the mounting the semiconductor element on the conductive plate, the plurality of semiconductor elements are mounted on the conductive plate; and wherein, in the disposing the resin material on the conductive plate, the plurality of semiconductor elements are sealed by the resin material.
It is preferable that the method further comprises, after removing the backside portion of the conductive plate, cutting the resin material in predetermined locations to form separate semiconductor devices each including at least one semiconductor element.
It is also preferable that, in the forming concave trenches in the conductive plate to form a plurality of segments, the concave trenches are formed in lattice-like arrangement; wherein, in the preparing a semiconductor element, a semiconductor wafer on which a plurality of semiconductor elements are formed is prepared; wherein, in the mounting the semiconductor element on the conductive plate, the semiconductor wafer is mounted on the conductive plate and electrodes of each semiconductor element formed in the semiconductor wafer are electrically coupled with corresponding segments of the plurality of segments via bumps; wherein, in the disposing the resin material on the conductive plate, the resin material fills a space between the semiconductor wafer and the conductive plate; and wherein the method further comprises, after removing the backside portion of the conductive plate, cutting the semiconductor wafer and the resin material in predetermined locations to form separate semiconductor devices each including at least one semiconductor element.
According to still another aspect of the present invention, there is provided a method of manufacturing a semiconductor device comprising: preparing a conductive plate; preparing a supporting sheet; sticking the conductive plate on the supporting sheet; cutting the conductive plate stuck on the supporting sheet to form a plurality of segments supported by the supporting sheet; preparing a semiconductor element; mounting a semiconductor element on at least one of the plurality of segments; and disposing resin material on the plurality of segments, wherein a part of the resin material enters at least a part of spaces between the segments.
In this case, it is preferable that the method further comprises peeling the supporting sheet, after disposing the resin material.
It is also preferable that the supporting sheet has opening portions at predetermined locations, and is made of material which does not adhere to solder; and wherein, in the cutting the conductive plate stuck on the supporting sheet to form a plurality of segments supported by the supporting sheet, at least one of the segments is exposed via the opening portions of the supporting sheet.
It is further preferable that the method further comprises electrically coupling electrodes of the semiconductor element with segments disposed around the at least one of the segments on which the semiconductor element is mounted via bonding wires; and wherein, in the disposing the resin material, the semiconductor element and the bonding wires are sealed by the resin material, and the resin material fills spaces between segments disposed around the at least one of the segments on which the semiconductor element is mounted.
It is advantageous that, in the preparing a semiconductor element, a semiconductor element having electrodes on which bumps are formed is prepared; wherein, in the mounting a semiconductor element on at least one of the plurality of segments, electrodes of the semiconductor element are electrically coupled with at least one of the segments located under the semiconductor element via the bumps; and wherein, in the disposing the resin material, the semiconductor element is sealed by the resin material, and the resin material fills spaces between segments disposed under the semiconductor element and spaces between the semiconductor element and the segments located under the semiconductor element.
It is also advantageous that, in the cutting the conductive plate stuck on the supporting sheet to form a plurality of segments supported by the supporting sheet, the conductive plate is cut into lattice-like arrangement, and the supporting sheet is not cut substantially.
It is further advantageous that, in the mounting a semiconductor element on at least one of the segments, the semiconductor element is mounted on the at least one of the segments via mounting material or tape-like adhesive.
It is preferable that the semiconductor element is a semiconductor integrated circuit chip.
It is also preferable that the semiconductor element is a diode chip; wherein, in the mounting the semiconductor element on at least one of the segments, the diode chip is mounted on one of the plurality of segments; wherein the method further comprises electrically coupling an electrode of the diode chip with one of the segments adjacent the divided segment on which the diode chip is mounted via a bonding wire; and wherein, in the disposing the resin material, the diode chip and the bonding wire are sealed by the resin material, and the resin material fills a space between the divided segment electrically coupled with the electrode of the diode chip and the divided segment on which the diode chip is mounted.
It is further preferable that the semiconductor element is a transistor chip; wherein, in the mounting the semiconductor element on at least one of the segments, the transistor chip is mounted on one of the plurality of segments; wherein the method further comprises electrically coupling electrodes of the transistor chip with two of the segments adjacent the divided segment on which the transistor chip is mounted via bonding wires; and wherein, in the disposing the resin material, the transistor chip and the bonding wires are sealed by the resin material, and the resin material fills spaces between the segments electrically coupled with the electrodes of the transistor chip and the divided segment on which the transistor chip is mounted.
It is advantageous that, in the disposing the resin material, the resin material is disposed by using a technology selected from a group consisting of molding by a metal die, coating, and potting.
It is also advantageous that, in the preparing a semiconductor element, a plurality of semiconductor elements are prepared; wherein, in the mounting the semiconductor element on at least one of the segments, the plurality of semiconductor elements are mounted on the segments; and wherein, in the disposing the resin material, the plurality of semiconductor elements are sealed by the resin material.
It is further advantageous that, in the cutting the conductive plate stuck on the supporting sheet to form a plurality of segments supported by the supporting sheet, the conductive plate is cut into lattice-like arrangement; wherein, in the preparing a semiconductor element, a semiconductor wafer on which a plurality of semiconductor elements are formed is prepared; wherein, in the mounting a semiconductor element on at least one of the plurality of segments, the semiconductor wafer is mounted on the plurality of segments supported by the supporting sheet, and electrodes of each semiconductor element formed on the semiconductor wafer are electrically coupled with corresponding segments of the plurality of segments via bumps; wherein, in the disposing resin material, the resin material fills a space between the semiconductor wafer and a plurality of segments supported by the supporting sheet and spaces between respective segments of the plurality of segments; and wherein the method further comprises cutting the semiconductor wafer and the resin material in predetermined locations to form separate semiconductor devices each including at least one semiconductor element.
According to still another aspect of the present invention, there is provided a method of manufacturing a semiconductor device comprising: preparing a semiconductor element having electrodes on which bumps are formed; preparing a conductive plate; forming a first set of concave trenches in a lattice-like arrangement on the face side of the conductive plate; forming a second set of concave trenches in a lattice-like arrangement on the backside of the conductive plate, the second set of concave trenches are shifted from the first set of concave trenches in the direction along the surface of the conductive plate; mounting the semiconductor element on the face surface of the conductive plate, wherein electrodes of the semiconductor element are electrically coupled with segments divided by the first set of concave trenches via bumps; filling a space between the semiconductor element and the conductive plate with resin material; and cutting the conductive plate at locations shifted in the directions along the surface of the conductive plate from the first and second sets of concave trenches.
In this case, it is preferable that, in the preparing a semiconductor element having electrodes on which bumps are formed, a semiconductor wafer on which a plurality of semiconductor elements are formed thereon is prepared, and each of the semiconductor element has electrodes on which bumps are formed; wherein, in the mounting the semiconductor element on the face surface of the conductive plate, the semiconductor wafer is mounted on the face surface of the conductive plate, and electrodes of each of the semiconductor elements are electrically coupled with segments divided by the first set of concave trenches via bumps; wherein, in the filling a space between the semiconductor element and the conductive plate with resin material, the resin material fill a space between the semiconductor wafer and the conductive plate; and wherein the method further comprises cutting the semiconductor wafer and the resin material in predetermined locations to form separate semiconductor devices each including at least one semiconductor element.
It is also preferable that the forming a second set of concave trenches in a lattice-like arrangement on the backside of the conductive plate is performed after filling a space between the semiconductor element and the conductive plate with resin material; wherein, in the forming a second set of concave trenches in a lattice-like arrangement on the backside of the conductive plate, the second set of concave trenches partially overlap the first set of the concave trenches and the conductive plate is separated by the first and second sets of concave trenches; and thereby obviating the cutting the conductive plate at locations shifted in the directions along the surface of the conductive plate from the first and second sets of concave trenches.
It is further preferable that, in the forming a first set of concave trenches in a lattice-like arrangement on the face side of the conductive plate and in the forming a second set of concave trenches in a lattice-like arrangement on the backside of the conductive plate, the first and second sets of concave trenches are formed by using a technology selected from a group consisting of half-cut dicing, half-etching and press working.
As mentioned above, in a semiconductor device according to the present invention, a plurality of segments or divided segments are formed from a conductor plate or board, and lead pad portions are constituted of the segments which are electrically coupled with electrodes of a semiconductor element. Therefore, by appropriately determining which divided segments are used as lead pad portions depending on the size and kind of each of the semiconductor elements, it is possible to commonly utilize the divided segments for the semiconductor elements having different sizes and kinds to form device packages. Also, it is possible to form die pad portions by using portions of the divided segments and to mount a semiconductor element on the die pad portions. In this case, other portions of the divided segments are used as lead pad portions and electrodes of the semiconductor element are electrically coupled with the lead pad portions. Alternatively, it is possible to electrically couple bumps provided on electrodes of a semiconductor element with divided segments to form lead pad portions. Thereby, it is possible to mount or dispose a semiconductor element in face-up condition or in face-down condition. The lead pad portions may be disposed in the periphery of the package, or may be disposed in the bottom portion of the package in lattice-like arrangement. The same standard conducting plate can be utilized to fabricate surface-mount type semiconductor devices having lead-less structure, even if the semiconductor devices have different sizes and/or kinds.
In the method of manufacturing a semiconductor device according to the present invention, segments or divided segments are defined by forming concave trenches in a conductor plate. A semiconductor element is mounted on the divided segments, and the semiconductor element and the divided segments are electrically coupled. Thereafter, the backside portion of the conductor plate is removed to form individual divided segments. Therefore, it is possible to easily perform a process of mounting a semiconductor element, a process of electrical connection between the semiconductor element and the divided segments, and a process of forming a package resin portion. Also, it is possible to fabricate a semiconductor device which has a plurality of lead pad portions finally insulated from each other. Therefore, according to the present invention, the number of parts and the number of process steps do not increase uselessly, and manufacturing process can be simplified.